Switch



T. BIRKENMAIER April 5, 1932.

SWITCH Filed April 19, 1929 3 Sheets-Sheet April 5, 1932. "r.BIRKENMAIER SWITCH Filed April 19, 1929 3 Sheets-Sheet 2 Patented Apr.5, 1932 UNIT STATES PATENT rice THEODORE BIRKENMAIER, OF ST. LOUIS,MISSOURI, ASSIGNOR TO W. N. MATTHEWS CORPORATION, OF ST. LOUIS,MISSOURI, A CORPORATION OF MISSOURI SXVITCH Application filed April 19,

This invention relates to switches and with regard to certain morespecific features, to fuse switches of the tubular type.

Among the several objects of the invention may be noted the provision ofan 11nproved type of a fuse switch wherein a tubular expulsion chamberis arranged for ready opening so that a fuse or switch link or the likemay be readily applied thereto; the provision of a device of the classdescribed which is adapted to operate advantageously with an improvedform of housing; and the provision of a device of the class describedwhich is economical and rugged in construction and simple in operation.Other objects will be in part obvious and in part pointed outhereinafter.

The invention accordingly comprises the elements and combinations ofelements, features of construction, and arrangements of parts which willbe exemplified in the structure herinafter described, and the scope ofthe application of which will be indicated in the following claims.

In the acompanying drawings, in which is illustrated one of variouspossible embodiments of the invention,

Fig. 1 is a vertical section taken through a closed switch box and fusecartridge comprising the invention;

Fig. 2 is a front elevation of Fig. 1, certain portions being brokenaway;

Fig. 3 is a bottom plan view of Fig. 1;

Fig. 4: is a view similar to Fig. 1, showing the door open and a fusecartridge in partially removed position;

Fig. 5 is a cross section taken on line 5-5 of Fig. 1; and,

Fig. 6 is a side elevation of a fuse cartridge per se, showing the samein open position and a fuse link partially applied, and also showing analternate position.

Similar reference characters indicate corresponding parts throughout theseveral views of the drawings.

Referring now more particularly to Fig. 1, there is illustrated atnumeral 1 a box, composed of non-conducting material, preferably ofporcelain. The box in its finished commercial form is preferably of aunitary recesses 13.

1929. Serial No. 356,359.

construction, the various members thereof being baked together andcomprising aback 3, a backwardly sloping top 5, side walls 7 and aseptum 9. Recesses 11 are provided in the rear for cementing on suitablesupporting means. The outer surfaces of the side walls 7 are providedwith elevations 8 for increasing the leakage path. The forward openingin the box has edges in which are formed longitudinal depressions orrecesses 13 for receiving the extending edges 14L of a door 15,

the door being so formed as to come flush with the front of said box 1.By this means a tortuous crack, rather than a straight one is effectedbetween the door and box, by means of which a better enclosing eflect ishad. The door 15 is hinged at the top of the box by means'of a pin 17 Atits lower end it is provided with an external finger piece 19 foropening and closing purposes.

Detents 21 are fastened to the upper end of said door 15. The detentsare preferably formed with a cross strip 22 for fastening purposes. Eachdetent is preferably of curved form and is positioned nearly flush withthe inner faces of the side walls 7' of the box, except that it has abent portion 23, the effect of which portion 23 is to press against thesaid inner faces so as to spring the detents 21 slightly inward andthereby frictionally hold the door shut.

Also, when the door is drawn open, as illus trated in Fig. 41, then thebent or curved portions 23 of the detents spring outwardly and drop intotheir respective longitudinal door The door is thus held in openposition. The economy of this construction is apparent, because it maybe seen that the same recesses 13 that serve as a door stop and to morecompletely close thebox against weather, also serve as recesses for theaction of the detents 21.

Cemented into the inside of the back 3 of the box 1 are suitable lineterminals 25, comprising wire sockets 27 and spring clips 29. Thesockets 27 are arranged with cross passages 31, each of which islaterally tapped for set screws for wire holding purposes. The pair ofset screws provided for each socket 27 may be used with either passage31, whereby wires may be brought in from either side of the switchthrough either combination of openings 33, or from one side only.

The spring clips 29 are of the type adapted to receive therebetween inelectrical contact the fiat sided terminal engaging elements of the fusecartridge C. The cartridge includes the upper element 35 having screwmeans 37 thereon for holding a fuse wire 38 in electrical contact, Thisupper element is also formed with a bridge portion 39 for hooking on aninsulated tool 40 for removing and applying the cartridge. A longgasexpulsive insulating tube 41 is fastened to the upper engagingelement 35 and surrounds said fuse link 38 down to a hair pin turn 43 onthe latter.

The insulating tube 41 passes with a snug fit through the lower terminalengaging element-35. It is not held 'to the same'with any device such asa set screw, because these have been found to damage the tube andpromote leakage, so that an are (such as is formed upon blowing)connects the terminals 35 over the shortest possible distance, namelythrough the portion of the tube 41 between said terminals.

The terminal engaging element 35 carries downwardly extending lugscooperating hingedly by means of a pin 62 with a lug 64, the latter lug64 being formed with what will be designated as a short, open-sided,insulating member or cover 45. It is preferable that the member 45 becomposed of fibre or the like and the lug 64 be formed integrallytherewith, also of fibre. The cross sectional shape of the tube 45 isshown as a crescent in Fig. 3 and comprises a solid portion 66 having alongitudinal open slot or opening 68 which is open when the tube 45 ishinged open as illustrated in Fig. 6. WVhen the tube 45 is hinged shut,as illustrated in Figs. 1 and 4, then the open side "of the slot 68 isclosed by the contiguous tube 41 against which the member 45 rests atthat time.

The lower terminal engaging element 35 is provided with a recess 70 intowhich the longitudinal opening 68 leads when the member 45 is closed.The recess is intersected by a set screw 53 threaded thereinto, the saidscrew serving .as a fastening for the fuse link when it is in connectedposition.

A further improvement of the lower terminal 35, taken in connection withthe septum 9, consists in said lower and rearward extension 51, which ineffect comprises two follower lugs 55, one on each side of the tube 41.These lugs engage the upper forwardly sloping surface of the septum 9.This upper surface, composed of porcelain, similar to the remainder ofthe box, is preferably glazed and is therefore smooth. It is to beunderstood that the septum may be constructed of otliier material suchas fiber, bakelite or the li e.

The septum 9 is provided with an opening 57 having an upper beveledportion 59 forwardly and a lower beveled portion 61 rearwardly, saidopening being adapted to receive the lower ends of the tubes 41, 45snugagainst the tube 41, whereby, in effect said i member 45 comprisespart of a tube, one wall of which is a portion of the wall of the tube41 (see Fig. 1). It is also to be noted that as the lower terminal isengaged, the cartridge tends to rotate therein, thereon effecting a re-1 action at point X (Fig. 4) so as to positively close the member 45 andform a complete tubular portion about the fuse link therein.

It will be seen that the septum is not at the lowermost region of thebox 1 but is raised somewhat, so that when the cartridge is in terminalengaging position then the lower end of the cartridge, for purposes ofprotection, is within the confines of the back 3, side I walls 7 anddoor 15.

The switch may be supplied with a fuse cartridge by opening the door tothe Fig. 4 position and inserting the lower end of the cartridge throughthe opening in the septum.

The member 45 is at this time manually held against the tube 41.

The lugs 55 limit the degree of insertion. This is an easy operationbecause the fit is loose.

lVhen the lugs strike the septum, the operator pushes the cartridge backinto the Fig. 1 position with the terminal engaging elements 35 withinthe confines of the terminals 29. At this time the lugs 55 ride up onthe sloping septum with the cartridge pivoting at point- X (Fig. 4) sothat there is always attained a proper and accurate engagement. No highdegree of skill nor care needs be exercised in pushing home thecartridge. Lugs 56 above the lugs 55 engage beneath the lower set ofspring clips 29 so as to prevent upward disconnecting movement of thecartridge when the reaction due to a blowing fuse is effected.

Removal is effected by applying the tool hook at bridge 39 and drawingdown the cartridge. It pivots on the lugs 55 until contact is broken andthen falls forward to a position slightly beyond the Fig. 4 position.After this the cartridge may be pulled out of the septum opening 57 byhand or with the tool.

The advantage of this construct-ion is that it greatly simplifies themanufacture. Also. the cartridge is positively placed in a positionwhere the lower open ends of the tubes are 3 gaging elements adapted tooutside of the box, so that when the cartridge blows gases are notengendered within the box.

The advantage of the cartridge per se is when it is withdrawn from thebox, the opensided cover member45 may be hinged open and the set screw53 withdrawn, whereupon the portion of the fuse in the recess 70 may bereadily removed. The other portion in the tube 41 may be removed fromthe upper end thereof by removing the cap screw 37.

Furthermore, when it is desired tore-insert a new fuse link, this mayreadily be done by feeding it through the tube all and fastening it atthe upper terminal engaging element by means of the screw 37. It maythen be readily bent around and fed into the recess 70 of the lowerterminal engaging element without the necessity for feeding it through asecond tube, such as would be required if the member were a stationarytube annexed to the tube d1. rafter the fuse link is fastened inposition as indicated by dotted lines in Fig. 6, the cover member 1:5may be brought into its closed position over its respective length offuse such as shown in Fi 1 or l and thereafter the fuse cartridge isready to be applied to the septum 9 as above de scribed. It will be seenthat the member 45 rests against the tube 41 and forms a second tubewhich is openable along its length and removable after having beenopened. In view of the above, it will be seen that the several objectsof the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructionswithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be inter Jreted as illustrative and not in alimiting sense.

I claim 1. A cartridge comprising terminal engaging elements spaced bynieans of a t a fuse link joining said terminal engagi g elements oneportion thereof passing through said tube and another lying outside ofthe same and a hinged member on one of the enswing against said tube andcover said outside part of the fuse link.

and another lying outside of the same where the tube extends beyond oneof the engaging elements and means hinged to said lastnamed engagingelement for covering and uncovering said external portion of the link.

4:. In a fuse switch a cartridge comprising terminal engaging elementsspaced by means of a tube, a fuse link joining said ten mina engagingelements one portion thereof passing through said tube and another lyingoutside of the same, a hinged member on one of the engaging elementsadapted to swing against said tube and cover said outside part of thefuse link, supporting means for the cartridge comprising means having anopening therein, line terminals, the periphery of said opening holdingthe hinged member to the tube when the line terminals are engaged by theterminal engaging elements.

A cartridge comprising terminal engaging elements spaced by means of atube, a

.se link joining said terminal engaging elements one portion thereofpassing through said tube and another ying outside of the same, a hingedmember on one of the engaging elements adapted to swing against saidtube and cover said outside part of the fuse link and means for holdingsaid hinged member to the tube.

6. A cartridge comprising terminal engaging elements spaced by means ofa tube, a fuse link joining said terminal engaging elements one portionthereof passing through said tube and another lying outside of the same,a hinged member on one of the engaging elements adapted to swing againstsaid tube and cover said outside part of the fuse link and means forholding said hinged member to the tube operable automatically when thecartridge is placed to make electrical contact.

7. A cartridge comprising terminal engaging elements, a fuse linkjoining said engaging elements and passing through a tube therebetween,a portion of said link lying externally of said. tube and a movableportion on one of the engaging elements adapted to cover and uncover theexternal portion of the link.

8. A cartridge comprising terminal engaging elements, a fuse linkjoining said engaging elements and passing through a tube therebetween,a portion of said link lying externally of said tube and a movableportion fastened to the cartridge adapted to cover and uncover theexternal portion of the link.

9. A cartridge comprising terminal engaging elements, fuse link joiningsaid engaging elements and passing through a tube therebetween, aportion of said link lying externally of said tube, a movable portionfastened to the cartridge adapted to cover and uncover the externalportion of the link and form a tube around said external portion of thelink.

10. In a fuse cartridge an upper terminal engaging element, a lowerterminal engaging element, a tube extending from the upper elementthrough the lower element, a re cess in said lower element, a swingableportion on the lower element having an open portion accommodating alength of fuse link, said open portion leading to and communicating withsaid recess, a fuse link fastened to the upper element and passingthrough the tube, a portion of said link lying outside of the tube andcomprising the length Within the swingable portion.

11. In a fuse switch, line terminals, a cartridge comprising terminalengaging elements spaced by means of a tube, a fuse link joining saidterminal engaging elements one portion thereof passing through said tubeand another lying outside of the same, a hinged member on one of the.engaging elements adapted to swing against said tube and cover saidoutside )art of the fuse link, supporting means for the cartridgecomprising means having an opening therein, the periphery of saidopening holding the hinged member to the tube.

12. In a fuse cartridge a tube, a juxtaposed cover, a fuse having a legin the tube and a leg under said cover, said uxtaposed cover beingmovable to uncover the fuse leg there under and hingeable on thecartridge to permit ready placement of said fuse.

In testimony whereof I have signed my name to this specification this17th day of April, 1929.

THEODORE BIR-KENMAIER.

